title: Kinetic separation of carbon dioxide and methane on a copper metal-organic framework.
abstract: Separation of carbon dioxide and methane is an important issue in upgrading low-quality natural gas. Adsorption equilibria and kinetics of CO(2) and CH(4) on a copper metal-organic framework (MOF), Cu(hfipbb)(H(2)hfipbb)(0.5) [H(2)hfipbb=4,4'-(hexafluoroisopropylidene) bis(benzoic acid)], were investigated to evaluate the feasibility of removing CO(2) from CH(4) in a pressure swing adsorption process using this new MOF adsorbent. The heat of adsorption of CO(2) on the Cu-MOF at zero-coverage (29.7 kJ/mol) is much lower than those on a carbon molecular sieve and a zeolite 5A adsorbent; and the heat of adsorption of CH(4) on the Cu-MOF (21.4 kJ/mol) is similar to that on the zeolite 5A adsorbent and smaller than that on a carbon molecular sieve. The Cu-MOF being investigated has apertures of (~3.5 × 3.5 Å), which favors the kinetically controlled separation of CO(2) and CH(4). The kinetic selectivity is found to be 26 at 298 K, and the overall selectivity (combining the equilibrium and kinetic effects) is about 25 for an adsorption separation process. These results suggest that the Cu-MOF adsorbent is an attractive alternative adsorbent for the CO(2)/CH(4) separation.
authors.affiliation: Chemical and Biological Engineering Department, Zhejiang University, Hangzhou 310027, China.
authors.forename: Zongbi
authors.initials: Z
authors.lastname: Bao
authors.forename: Sufian
authors.initials: S
authors.lastname: Alnemrat
authors.forename: Liang
authors.initials: L
authors.lastname: Yu
authors.forename: Igor
authors.initials: I
authors.lastname: Vasiliev
authors.forename: Qilong
authors.initials: Q
authors.lastname: Ren
authors.forename: Xiuyang
authors.initials: X
authors.lastname: Lu
authors.forename: Shuguang
authors.initials: S
authors.lastname: Deng
mesh_terms: D000327:Adsorption; D002245:Carbon Dioxide / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D006358:Hot Temperature; D007700:Kinetics; D008697:Methane / Q000737:chemistry*; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry; D016062:Porosity
chemical_list: D009942:Organometallic Compounds; D002245:Carbon Dioxide; D003300:Copper; D008697:Methane